title: Delineation of the watershed between right and left hepatic arterial territories with carbon dioxide-enhanced ultrasonography.
abstract: OBJECTIVE
  To delineate the watersheds between hepatic arterial territories and their variations with the use of CO(2)-enhanced ultrasonography (US) and to compare the results with segmental anatomy as described by Couinaud.
  
  
  METHODS
  From March 2004 to January 2005, this study recruited 31 patients (18 men and 13 women; mean age, 63 years; range, 47-77 y) with hepatocellular carcinoma (HCC) who were scheduled to receive transarterial chemoembolization. After serial angiography, CO(2)-enhanced US was performed with catheters superselectively inserted into the hepatic arteries. The territorial divisions between hepatic arteries were compared with the anatomic courses of the middle and left hepatic veins. Data from 17 patients were used to assess the vascular territories of the right and left lobe and data from the remaining 14 patients were used to assess those of the left medial and left lateral segments.
  
  
  RESULTS
  Mapped arterial territories exactly matched Couinaud segments in 17 of 31 patients (54.8%). They did not coincide with Couinaud segments in 45.2% of patients with HCC. Crossover enhancement was noted over the right and left lobes and over the left medial and lateral segments in seven patients each. Two tumors located exactly in watershed areas showed CO(2) enhancement across the hepatic vein.
  
  
  CONCLUSIONS
  CO(2)-enhanced US is useful to delineate arterial territories of hepatic segments and show crossover arterial supply compared with Couinaud segments. Awareness of crossover arterial supply is important for chemoembolization, segmental chemoembolization, hepatic arterial infusion, sonography, and surgery.
authors.affiliation: Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan. chenranchou@yahoo.com.tw
authors.forename: Ran-Chou
authors.initials: RC
authors.lastname: Chen
authors.forename: Chen-Te
authors.initials: CT
authors.lastname: Chou
authors.forename: Wei-Tsung
authors.initials: WT
authors.lastname: Chen
authors.forename: Tom
authors.initials: T
authors.lastname: Chen
authors.forename: Jiunn-Ming
authors.initials: JM
authors.lastname: Lii
authors.forename: Dachen
authors.initials: D
authors.lastname: Chu
mesh_terms: D000368:Aged; D015901:Angiography, Digital Subtraction; D002245:Carbon Dioxide; D006528:Carcinoma, Hepatocellular / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000628:therapy; D016461:Chemoembolization, Therapeutic; D016009:Chi-Square Distribution; D003097:Collateral Circulation; D003287:Contrast Media; D005260:Female; D006499:Hepatic Artery / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006503:Hepatic Veins / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008099:Liver / Q000098:blood supply*; D008102:Liver Circulation; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D055420:Perfusion Imaging / Q000379:methods*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013624:Taiwan; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D002245:Carbon Dioxide